My Lords, I am pleased to be able to continue the debate that was adjourned on Monday. In proposing my Amendment 175A, which is to do with blue-green flood-risk management, I follow some excellent speeches on Monday evening, including ones from the noble Lord, Lord Cameron, on nature-based solutions, and the noble Lord, Lord Teverson, on grey water. Alongside blue-green, these solutions are all about the need for an integrated, holistic system of preserving the water supply and dealing with wastewater and storm-water.
It is obvious to say this: rain is valuable and belongs to nobody, but its supply is limited and therefore it needs to be used sparingly. It is sometimes used too much and sometimes used too little. There is too much of it and too little. In the home, as the noble Lord, Lord Teverson, said—and I certainly support his amendment—separating grey water is a great idea. I have also heard that there is more to do because, apparently, some washing machine manufacturers refuse to guarantee machines if rainwater is used. Obviously, you would not use grey water, but it seems to me that rainwater could be used. Why is it not used? It is another source of water, rather than using processed fresh drinking water.
Putting rain into sewers, which then causes overflowing, adds massively to the carbon footprint with pumping and treatment. I spent some time in the last few years wondering why it was necessary for the Thames Tideway Tunnel to be built—not because I did not want the
River Thames cleaned up, but because the evidence shows that the water in the Thames meets all the regulations now and, if it were to be started today, the tunnel would be found to not be needed. This is a £5 billion project and what nobody seems to remember or think is that pumping the water from very deep shafts, as they will be when they get to the end, and treating the water, which is mostly either flood-water or river water, creates an enormous carbon footprint. If blue-green had been started and was working by then, this could have all been avoided. Also, of course, it would have created quite a few jobs locally, less skilled than those needed for the tunnelling and all the other work that goes into the Thames Tideway Tunnel. We must always recognise that big contractors love these big jobs—a bit like HS2—and there is often benefit in having smaller work done by possibly less skilled and local workers.
However, that is a slight diversion and I will explain to the Committee a little more about blue-green. It is the idea of keeping as much rainwater as possible out of the sewers. It is quite simple really. There are several ways of doing it. The first one, and the easiest one for many people to understand, is to make sure that the rainwater drains from the roofs of properties and does not go into the sewerage system. It should go into soakaways. Soakaways are suitable in many areas but in other areas maybe they are not.
You can say the same about the run-off from roads, car parks and other hard surfaces. It does not really matter whether they are municipally owned, government-owned or privately owned. It is quite possible—it has been done in a number of cities in the United States—to convert some of these what you might call waterproof surfaces into more absorbent ones and/or build soakaways underneath parks to reduce the peak flows into sewers, so that some of the peak flow goes into what I am calling soakaways. Of course, you carry on by separating the outcomes from these soakaways from the sewage going to sewerage works. The outcome from the soakaways goes into the watercourses and rivers.
This is much easier to do with new builds but one bit of work done in connection with the Thames Tideway Tunnel alternative was to look at the two foul sewers going round, I think¸ London’s Sloane Street, both of which are mixed rainwater and sewage. It would not have been that difficult to convert one into one and one into the other rather than having both having a mix. Retrofitting is also something to be looked at; it would certainly reduce the water rates in existing properties. For new builds, it is obvious. I hope Ministers will look at that with some interest.
One of the other problems which blue-green obviously has, and some of the other solutions may have as well, is the need for so many different bodies to facilitate them—local authorities, obviously, water companies, river authorities, highways authorities, building control, commercial companies, as well as residents. One also needs to look at a way of incentivising people to want to do this. For example, residents might see a reduction in their water or sewerage charges if they accept not putting their rainwater into the sewers. All these things need looking at.
To conclude proposing my amendment and supporting the other two I mentioned, together, we have given the Minister a good package of measures to reduce floods, sewage overflows and carbon footprints, all of which are achievable at not too high a cost, by different means and in different circumstances. In responding to this group, I hope the Minister says that he will take away my amendment and the other two, and come back with one combined proposal to sort out all these issues to the benefit of the environment, water quality, costs and the environmental footprint.